The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
As the internal control systems of passenger cars and light trucks increasingly move from full mechanical systems such as throttle connections and gear selection to full electronic systems in which such mechanical connections are replaced by electrical sensors, microprocessors and servo devices, a constant goal is to provide not only the same performance, response and operator feel but also improved performance, reliability and safety.
One of the current features of such ongoing development is the electronic transmission range select (ETRS). In this device, a transmission shift lever having an orthogonal range of motion such as longitudinal, i.e., front to rear with one or more lateral, i.e., side to side, paths, essentially mimics a conventional shift lever which is linked mechanically to the transmission. However, in its modern configuration, the mechanical linkage is eliminated and replaced with, for example, position sensors at the shift lever, a transmission control module (TCM) and one or more solenoids or servo devices that effect range and/or gear selection of the transmission. For example, the shift lever may comprehend four physical positions: R (reverse), N (neutral), Null and D (drive) and it is spring biased to return to the Null position. In order for the operator to select certain active gear ranges, an interlock button, typically located on the side of the shift lever, must first be depressed and the shift lever must remain in the newly selected position for a certain minimum time in order for the system to validate and act upon a shift request.
As stated above, the goal of this and other electronic systems is to safely provide improved operator feel, response and performance. This goal may represent a significant challenge as safety considerations such as requiring a delay between gear selections and the activation of the interlock button may interfere with acting upon rapid operator inputs.
The present invention is directed to improving the driving experience with transmissions equipped with electronic transmission range select systems and ensuring that all operator commands are acted upon.